So to summarise the issue:
- Trezor got "wiped" during firmware upgrade, restored from seed, can only see transactions (wallets?
) up to October 2017.
The only reasons that I can think of for what the OP is experiencing is:
1. They somehow managed to use address(es) out past the default "Gap Limit" in Trezor. So, when restoring the wallet, the Trezor is not able to detect that these address have funds and therefore does not display them. (NOTE: This is more common with Ledger Nano S when people use the "sign message" functionality to manually select an address)
FIX: Connect the Trezor to Electrum (using "Hardware Device" option), and then manually generate 100 "receive" addresses and 100 "change" addresses and see if the funds show up.
2. The OP had multiple "accounts" created in their Trezor and for some reason Trezor hasn't restored them all.
FIX: You'll need to try adding new "accounts" to the Trezor wallet to see if that starts showing up your funds. If not, maybe use Electrum and restore wallets (using BIP39 option + your recovery seed) and manually select the derivation path for the extra accounts:
- m/44'/0'/1'
- m/44'/0'/2'
...
- m/44'/0'/n'
3. The OP actually had transactions on a different coin like BCH or BTG etc and hasn't restored those within the Trezor.
FIX: Check other "coins" within the Trezor wallet to see if they show the transactions you're looking for.